Gravity hot water system plumbed into central heating circuit.

[Alan Rothwell]

Any body seen this b4?
I have just moved into a bungalow and it has a Baxi Boston boiler installed around 20yrs ago (still working). Whilst up in the loft I noticed there was only one cold water tank and no header tank for the central heating. The hot water and central heating vent both discharge into the same tank! The system has no motorised valve, one side of the boiler flow & return is 22mm pumped CH and the other 28mm hot water circuit that goes to the hot water cylinder. I drained the system down and left the tank open and checked and it was filling the CH circuit up. I cannot find where it feeds into it yet and iv had numerous floorboards up. Anybody seen this b4?

 

[Riley]

Primatic cylinder?

 

[Alan Rothwell]

Not sure never seen one b4, just had a quick read and it would make sense on where it' filling up from. Thanks

 

[Riley]

No pumps or chemicals

 

[jtsplumbing]

That brings back some memories, nothing much to go wrong but you would be better to convert to fully pumped, but that would need new cylinder roof tank and controls, then find someone who knows how to do it.

 

[Alan Rothwell]

I’m getting the system changed to a combi, it was bugging me how the system worked.